70 The Irish Naturalist. [ March, 



discovered in the tilting-up of the older stratified rocks, and 

 in their frequently folded and contorted condition, though 

 they were, naturally, as sediments, laid down horizontally. 



Evidence of such oscillations of level is of world-wide 

 occurrence. Upheaval is shown in the fossil remains of 

 marine animals found in rocks, now far from the sea, such as 

 those under our feet, and in the more superficial layers of clay 

 or sand, often at great heights above the sea-level, these 

 layers sometimes containing the remains of animals belonging 

 to species still existing in the neighbouring ocean. Sub- 

 sidence may be caused either by secular movements of the 

 crust, as aforesaid, or by volcanic disturbance. Proofs of 

 depression are to be found in the fjords on the coasts of 

 Norway, Scotland, and Ireland, and other countries, which are 

 nothing more than submerged valleys or glens ; and that the 

 west coast of Greenland is also sinking is shown by the sea 

 having risen over ancient buildings and islets within historic 

 times. As an instance of elevation and depression of limited 

 extent the area on which the Temple of Jupiter Serapis stands 

 at Pozzuoli in the Bay of Naples, is one of the best known. 

 The columns of this ruin, at a height of iofeet 5 inches above 

 the base, show perforations made in the marble by boring 

 Molluscs (Lithodomus, &c), whose shells have been extracted 

 from the cavities they made, proving that the temple had 

 sunk down below the level of the sea. Inscriptions show that 

 it was in existence in the year 194 a.d. It was ascertained to 

 be slowly sinking again in the early part of the present 

 century. 1 



We may now ask how fossils became embedded in the 

 rocks. The prolonged and gradual subsidence of the sea- 

 bottom during the earlier part of the Carboniferous Period 

 resulted, as we have shown, in the accumulation of a great 

 thickness of sediment, in the piling-up of which the shells of 

 molluscs, and brachiopods, and the calcareous plates of 



1 Those who wish for more detailed information concerning this 

 remarkable ruin, interesting alike to the archaeologist and to the 

 geologist, should consult the following:— "Observations on the Temple 

 of Serapis," by C. Babbage Quart. Journ. Geol. Soc, vol. iii., 1847, p. 

 186. " Principles of Geology," Lyell. Geological Magazine, June, 1892, 

 p. 282 . J. E. H. Thomson, in a letter to the editor on " The Temple of 

 Jupiter Serapis in Puteoli (Pozzuoli)." 



